Novel amidines

ABSTRACT

Phenylformamidines of the formula ##STR1## wherein each of R 1 , R 2  and R 3  represents hydrogen, C 1  -C 4  -alkyl, C 1  -C 4  -alkoxy, halogen or trifluoromethyl, R 4  represents C 1  -C 4  -alkyl and A represents --CH 2  --CH 2  --, --CH 2  --CH 2  --CH 2  --, ##STR2## a process for their manufacture and their use in pest control.

The present invention relates to phenylformamidines and salts thereofwith inorganic and organic acids, to a process for their manufacture andto their use in pest control.

The phenylformamidines have the formula ##STR3## wherein each of R₁, R₂and R₃ represents hydrogen, C₁ -C₄ alkyl, C₁ -C₄ alkoxy, halogen ortrifluoromethyl, R₄ represents C₁ -C₄ alkyl and A represents --CH₂ --CH₂--, --CH₂ --CH₂ --CH₂ --, ##STR4##

By halogen is meant fluorine, chlorine, bromine or iodine, in particularchlorine or bromine. The alkyl and alkoxy groups represented by R₁ to R₄can be straight-chain or branched. Examples of such groups include:methyl, methoxy, ethyl, ethoxy, propyl, propoxy, isopropyl, n-butyl,isobutyl, sec-butyl, tert-butyl.

Examples of possible inorganic acids for the salt-formation are: HCl, H₂SO₄, HBr, and H₃ PO₄, and examples of organic acids are saturated orunsaturated mono-, di- and tricarboxylic acids, for example formic acid,acetic acid, oxalic acid, phthalic acid, succinic acid and citric acid.

Preferred compounds are those of the formula I wherein R₁ representschlorine, bromine, methyl, ethyl, isopropyl or trifluoromethyl, each ofR₂ and R₃ represents hydrogen, chlorine, bromine, methyl, ethyl,isopropyl or trifluoromethyl, and A represents ##STR5##

The phenylformamidines of the formula I can be obtained by methods whichare known per se, for example by reacting a compound of the formula##STR6## wherein R₁, R₂ and R₃ are as defined in formula I, with acompound of the formula ##STR7## wherein A is as defined in formula Iand R represents C₁ -C₅ alkyl.

The process is carried out at a temperature between 0° and 120° C.,preferably between 10° and 50° C., under normal or elevated pressure andoptionally in a solvent or diluent. Examples of suitable solvents ordiluents are: ethers and ethereal compounds, such as dioxane,dimethoxyethane and tetrahydrofurane; amides, such as N,N-dialkylatedcarboxamides; aliphatic, aromatic and halogenated hydrocarbons, inparticular benzene, toluene, xylene, chloroform and chlorobenzene;nitriles, such as acetonitrile; dimethyl sulphoxide, ketones, such asacetone and methyl ethyl ketone.

The starting materials of the formulae II and III are kwown or they canbe prepared by methods analogous to known ones.

The compounds of the formula I are suitable for controlling a variety ofanimal and plant pests. They possess nematicidal properties and can beused for example to control phytopathogenic nematodes. They are alsosuitable for controlling viruses, bacteria and phytopathogenic fungi. Inparticular, the compounds of the formula I are suitable for controllinginsects, phytopathogenic mites and ticks, for example of the orders:Lepidoptera, Coleoptera, Homoptera, Heteroptera, Diptera, Acarina,Thysanoptera, Orthoptera, Anoplura, Siphonaptera, Mallophaga, Thysanura,Isoptera, Psocoptera and Hymenoptera.

In particular, the compounds of the formula I are suitable forcontrolling insects which are harmful to plants, especially insectswhich damage plants by eating, in ornamentals and crops of usefulplants, especially in cotton plantations (e.g. Spodoptera littoralis andHeliothis virescens) and in vegetable crops (for example Leptinotarsadecemlineata and Myzus persicae).

The active compounds of the formula I also have a very good actionagainst flies, for example Musca domestica and mosquito larvae.

The insecticidal and/or acaricidal action can be substantially broadenedand adapted to prevailing circumstances by addition of otherinsecticides and/or acaricides. Examples of suitable additives include:organic phosphorus compounds, nitrophenols and derivatives thereof,formamidines, ureas, pyethroids, carbamates, and chlorinatedhydrocarbons.

Compounds of the formula I are also combined with particular advantagewith substances which exert a potentiating effect. Examples of suchcompounds include: piperonyl butoxide, propynyl ether, propynyl oximes,propynyl carbamates and propynyl phosphonates,2-(3,4-methylenedioxyphenoxy)-3,6,9-trioxaundecane,S,S,S-tributylphosphorotrithioate.

The compounds of the formula I may be used as pure active substance ortogether with suitable carriers and/or additives. Suitable carriers andadditives can be solid or liquid and correspond to the substancesconventionally used in the art of formulation, for example natural orregenerated substances, solvents, dispersants, wetting agents,tackifiers, thickeners, binders and/or fertilisers.

For application, the compounds of the formula I may be processed todusts, emulsifiable concentrates, granules, dispersions, sprays, tosolutions, or suspensions, in the conventional formulation which iscommonly employed in application technology. In addition, cattle dipsand spray races, in which aqueous preparations are used, may also bementioned.

The compositions of the present invention are prepared in known mannerby homogeneously mixing and/or grinding active substances of the formulaI with the suitable carriers, with or without the addition ofdispersants or solvents which are inert to the active substances.

The compounds of the formula I may be processed to the followingformulations:

Dusts, tracking powders and granules (coated granules, impregnatedgranules and homogeneous granules). Liquid formulations:

(a) water-dispersible active substance concentrates: wettable powders,pastes and emulsions;

(b) solutions.

The content of active substance in the above described compositions isbetween 0.1% and 95%.

The compounds (active substances) of the formula I can, for example, beformulated as follows (throughout the present specification all partsand percentages are by weight):

Dusts

The following substances are used to manufacture (a) a 5% and (b) a 2%dust:

(a)

5 parts of active substance,

95 parts of talc;

(b)

2 parts of active substance,

1 part of highly disperse silicic acid,

97 parts of talc.

The active substances are mixed with the carriers and ground.

Granules

The following substances are used to produce 5% granules:

5 parts of active substance,

0.25 parts of epichlorohydrin,

0.25 parts of cetyl polyglycol ether,

3.50 parts of polyethylene glycol,

91 parts of kaolin (particle size 0.3-0.8 mm).

The active substance is mixed with epichlorohydrin and the mixture isdissolved in 6 parts of acetone; the polyethylene glycol and cetylpolyglycol ether are then added. The resultant solution is sprayed onkaolin, and the acetone is subsequently evaporated in vacuo.

Wettable powders

The following constituents are used for the preparation of (a) a 40%,(b) and (c) a 25%, and (d) a 10% wettable powder:

(a)

40 parts of active substance,

5 parts of sodium ligninsulphonate,

1 part of sodium dibutylnaphthalenesulphonate,

54 parts of silicic acid.

(b)

25 parts of active substance,

4.5 parts of calcium ligninsulphonate,

1.9 parts of Champagne chalk/hydroxyethyl cellulose mixture (1:1),

1.5 parts of sodium dibutylnaphthalenesulphonate,

19.5 parts of silicic acid,

19.5 parts of Champagne chalk,

28.1 parts of kaolin,

(c)

25 parts of active substance,

2.5 parts of isooctylphenoxy-polyoxyethyleneethanol,

1.7 parts of Champagne chalk/hydroxyethyl cellulose mixture (1:1),

8.3 parts of sodium aluminium silicate,

16.5 parts of kieselguhr,

46 parts of kaolin;

(d)

10 parts of active substance,

3 parts of a mixture of the sodium salts of saturated fatty alcoholsulphates,

5 parts of naphthalenesulphonic acid/formaldehyde condensate,

82 parts of kaolin.

The active substances are homogeneously mixed with the additives insuitable mixers and the mixture is then ground in appropriate mills androllers. Wettable powders are obtained which can be diluted with waterto give suspensions of the desired concentration.

Emulsifiable concentrates

The following substances are used to produce (a) a 10%, (b) a 25% and(c) a 50% emulsifiable concentrate:

(a)

10 parts of active substance,

3.4 parts of epoxidised vegetable oil,

3.4 parts of a combination emulsifier consisting of fatty alcoholpolyglycol ether and alkylarylsulphonate calcium salt,

40 parts of dimethyl formamide,

43.2 parts of xylene;

(b)

25 parts of active substance,

2.5 parts of epoxidised vegetable oil,

10 parts of alkylarylsulphonate/fatty alcohol polyglycol ether mixture,

5 parts of dimethyl formamide,

57.5 parts of xylene;

(c)

50 parts of active substance,

4.2 parts of tributylphenol-polyglycol ether,

5.8 parts of calcium dodecylbenzenesulphonate,

20 parts of cyclohexanene,

20 parts of xylene.

By diluting these concentrates with water it is possible to obtainemulsions of the required concentration.

Sprays

The following ingredients are used to prepare (a) a 5% spray, and (b) a95% spray:

(a)

5 parts of active substance,

1 part of epichlorohydrin,

94 parts of ligroin (boiling range 160°-190° C.);

(b)

95 parts of active substance,

5 parts of epichlorohydrin.

The invention is further illustrated by the following Examples.

EXAMPLE 1 Preparation ofN-(2,6-diethylphenyl)-N'-methyl-N'-(5,5-dimethyl-1,3-dioxan-2-yl)-formamidine

To a solution of 8.1 g of N-(2,6-diethylphenyl)-N'-methylformamidine in20 ml of CH₂ Cl₂ are added 13.5 g of5,5-dimethyl-2-triethylammonium-1,3-dioxolan-tetrafluoroborate (cf.Synth. 1971, 312). The reaction mixture is stirred for 14 hours at roomtemperature, cooled to 0° C. after addition of 100 ml of ether, and theprecipitated triethylammonium tetrafluoroborate is collected byfiltration. The filtrate is concentrated and the product isrecrystallised from hexane, giving the compound of the formula ##STR8##with a melting point of 72° C.

The following compounds can also be prepared in analogous manner:

    ______________________________________                                         ##STR9##                                                                     R.sub.1                                                                              R.sub.2  R.sub.3  R.sub.4                                                                             R.sub.5                                                                            Physical data                             ______________________________________                                        2-CH.sub.3                                                                           H        H        CH.sub.3                                                                            CH.sub.3                                                                           n.sub.D.sup.20° =1.5407            2-Cl   4-Cl     5-Cl     CH.sub.3                                                                            CH.sub.3                                                                           n.sub.D.sup.20° =1.5492            2-CH.sub.3                                                                           4-Cl     H        CH.sub.3                                                                            CH.sub.3                                                                           n.sub.D.sup.20° =1.5358            2-C.sub.3 H.sub.7(i)                                                                 H        6-C.sub.3 H.sub.7(i)                                                                   CH.sub.3                                                                            CH.sub.3                                                                           m.p.: 136° C.                      2-CH.sub.3                                                                           4-Cl     H        CH.sub.3                                                                            C.sub.2 H.sub.5                                                                    m.p. :83° C.                       3-Cl   H        5-Cl     CH.sub.3                                                                            CH.sub.3                                                                           n.sub.D.sup.22° =1.5513            3-CF.sub.3                                                                           H        5-Cl     CH.sub.3                                                                            CH.sub.3                                                                           n.sub.D.sup.22° =1.4743            2-CH.sub.3                                                                           H        6-CH.sub.3                                                                             CH.sub.3                                                                            CH.sub.3                                                                           n.sub.D.sup.22° =1.5232            2-CH.sub.3                                                                           4-CF.sub.3                                                                             H        CH.sub. 3                                                                           CH.sub.3                                                                           m.p.: 84° C.                       2-CH.sub.3                                                                           4-CH.sub.3                                                                             5-CH.sub.3                                                                             CH.sub.3                                                                            CH.sub.3                                                                           m.p.: 60-67° C                                                         (wax-like)                                2-CH.sub.3                                                                           4-Cl     5-CH.sub.3                                                                             CH.sub.3                                                                            C.sub.2 H.sub.5                                                                    n.sub.D.sup.22° =1.5421            2-Cl   4-Cl     H        CH.sub.3                                                                            CH.sub.3                                                                           n.sub.D.sup.22° =1.5560            2-Cl   4-Cl     H        CH.sub.3                                                                            C.sub.2 H.sub.5                                                                    m.p.: 55°-62° C.                                                (wax-like)                                2-CH.sub.3                                                                           3-CH.sub.3                                                                             H        CH.sub.3                                                                            CH.sub.3                                                                           n.sub.D.sup.22° =1.5360            2-CH.sub.3                                                                           3-CH.sub.3                                                                             H        CH.sub.3                                                                            C.sub.2 H.sub.5                                                                    m.p.: 43° C.                       2-CH.sub.3                                                                           4-CH.sub.3                                                                             H        CH.sub.3                                                                            CH.sub.3                                                                           m.p.: 50° C.                       2-CH.sub.3                                                                           4-CH.sub.3                                                                             H        CH.sub.3                                                                            C.sub.2 H.sub.5                                                                    m.p.: 56° C.                       2-CH.sub.3                                                                           4-Br     H        CH.sub.3                                                                            CH.sub.3                                                                           m.p.: 67° C.                       2-CH.sub.3                                                                           4-Br     H        CH.sub.3                                                                            C.sub.2 H.sub.5                                                                    m.p.: 65-72° C.                                                        (wax-like)                                2-CH.sub.3                                                                           4-OCH.sub.3                                                                            H        CH.sub.3                                                                            CH.sub.3                                                                           n.sub.D.sup.22° =1.5434            2-CH.sub.3                                                                           4-OCH.sub.3                                                                            H        CH.sub.3                                                                            C.sub.2 H.sub.5                                                                    n.sub.D.sup.22° =1.5377            2-CH.sub.3                                                                           H        6-C.sub.2 H.sub.5                                                                      CH.sub.3                                                                            CH.sub.3                                                                           n.sub.D.sup.22° =1.5282            2-CH.sub.3                                                                           H        6-C.sub.2 H.sub.5                                                                      CH.sub.3                                                                            C.sub.2 H.sub.5                                                                    n.sub.D.sup.22° =1.5197            2-Cl   H        6-Cl     CH.sub.3                                                                            CH.sub.3                                                                           n.sub.D.sup.22° =1.5477            2-Cl   H        6-Cl     CH.sub.3                                                                            C.sub.2 H.sub.5                                                                    m.p.: 73° C.                       H      4-OC.sub.2 H.sub.5                                                                     H        CH.sub.3                                                                            CH.sub.3                                                                           n.sub.D.sup.22° =1.5414            H      4-OC.sub.2 H.sub.5                                                                     H        CH.sub.3                                                                            C.sub.2 H.sub.5                                                                    n.sub.D.sup.22° =1.5334            2-CH.sub.3                                                                           4-Cl     H        C.sub.2 H.sub.5                                                                     CH.sub.3                                                                           n.sub.D.sup.22° =1.5457            2-CH.sub.3                                                                           4-Cl     H        C.sub.2 H.sub.5                                                                     C.sub.2 H.sub.5                                                                    n.sub.D.sup.22° =1.5359            2-CH.sub.3                                                                           4-Cl     H        C.sub.4 H.sub.9(i)                                                                  CH.sub.3                                                                           n.sub.D.sup.20  =1.5259                   2-CH.sub.3                                                                           4-CH.sub.3                                                                             H        C.sub.4 H.sub.9(n)                                                                  CH.sub.3                                                                           n.sub.D.sup.20  =1.4983                   ______________________________________                                    

    ______________________________________                                         ##STR10##                 N.sub.D.sup.20°  = 1.5592                    ##STR11##                 n.sub.D.sup.20°  = 1.5624                    ##STR12##                 n.sub.D.sup.20°  - 1.554                     ##STR13##                 n.sub.D.sup.20°  = 1.5679                    ##STR14##                                                                    R.sub.1   R.sub.2     R.sub.3     Physical data                               ______________________________________                                        2-CH.sub.3                                                                              4-CH.sub.3  H           n.sub.D.sup.20°  = 1.5321            2-CH.sub.3                                                                              4-CH.sub.3  5-CH.sub.3  n.sub.D.sup.20°  = 1.5234            2-CH.sub.3                                                                              93   4-Cl   5-Cl        m.p.: 78° C.                         2-CH.sub.3                                                                              4-Br        H           m.p.: 61° C.                         2-CH.sub.3                                                                              4-Cl        H           m.p.: 68° C.                         2-Cl      H           6-Cl        n.sub.D.sup.20°  = 1.5145            2-CH.sub.3                                                                              H           6-C.sub.2 H.sub.5                                                                         n.sub.D.sup.20°  = 1.5198            2-CH.sub.3                                                                              4-OCH.sub.3 H           n.sub.D.sup.20°  = 1.5341            2-CH.sub.3                                                                              4-CF.sub.3  H           n.sub.D.sup.20°  = 1.4987            2-CH.sub.3                                                                              4-OC.sub.2 H.sub.5                                                                        H           n.sub.D.sup.20°  = 1.5349             ##STR15##                 m.p.: 65° C.                                ______________________________________                                    

example 2 (a) insecticidal stomach poison action

Cotton plants were sprayed with a 0.05% aqueous emulsion of activesubstance (obtained from a 10% emulsifiable concentrate). After thespray coating had dried, the cotton plants were populated withSpodoptera littoralis and Heliothis virescens in the L₃ -stage. The testwas carried out at 24° C. and 60% relative humidity.

In this test, the compounds of Example 1 exhibited a good insecticidalstomach poison action against Spodoptera and Heliothis larvae.

(B) Systemic insecticidal action

To determine the systemic action, bean plants (Vicia fabia) which hadgrown roots were put into a 0.01% aqueous solution of active substance(obtained from a 10% emulsifiable concentrate). Twenty four hours later,the parts of the plants above the soil were populated with aphids (Aphisfabae). By means of a special device the aphids were protected from anypossible contact with the test substance either directly or via the gasphase. The test was carried out at 24° C. and 70% relative humidity.

In this test, the compounds of Example 1 exhibited a systemicinsecticidal action against Aphis fabae.

EXAMPLE 3 Action against Chilo suppressalis

Rice seedlings of the variety Caloro were transplanted into plastic pots(6 plants per pot) having a diameter of 17 cm at the top and reared to aheight of about 60 cm. Infestation with Chilo suppressalis larve (L₁-stage, 3 to 4 mm in length) took place two days after the addition ofactive substance in granule form (rate of application: 8 kg of activeingredient per hectare) to the paddy water. Evaluation of theinsecticidal action was made 10 days after addition of the granules. Inthis test, the compounds of Example 1 acted against Chilo suppressalis.

EXAMPLE 4 Acaricidal action

Twelve hours before the test for acaricidal action, Phaseolus vulgarisplants were populated with an infested piece of leaf from a mass cultureof Tetranychus urticae. The mobile stages which had migrated to theplants were sprayed with the emulsified test preparations from achromatography atomiser in such a way that the spray broth did not runoff. The number of living and dead larvae, adults and eggs was evaluatedunder a stereoscopic microscope after 2 and 7 days and the resultexpressed in percentage values. During the test run, the plants stood ingreenhouse compartments at 25° C.

In this test, the compounds of Example 1 acted against adults, larvaeand eggs of Tetranychus urticae.

EXAMPLE 5 Action against soil nematodes

To test the action against soil nematodes, the active substances werehomogeneously mixed with soil infected with root gall nematodes(Meloidgyne arenaria). Young tomato plants were planted in the treatedsoil in one test run immediately afterwards and then 8 days laterfurther tomatoes were sown in a second test run.

The nematicidal action was evaluated by counting the number of gallspresent on the roots 28 days after planting and sowing respectively. Inthis test, the active compounds of Example 1 exhibited a good actionagainst Meloidogyne arenaria.

EXAMPLE 6 Action on ticks

(A) Rhipicephalus bursa

Five adult ticks and 50 tick larvae were counted into each of a numberof test tubes and immersed for 1 to 2 minutes in 2 ml of an aqueousemulsion containing a concentration of 100, 10, 1 or 0.1 ppm of testsubstance. Each test tube was then sealed with a cotton-wool plug andplaced on its head to enable the cotton wool to absorb the activesubstance emulsion. Evaluation of the action against adults was madeafter 2 weeks and of that against larvae after 2 days. Each test wasrepeated twice.

(B) Boophilus microplus (larvae)

Tests were carried out with 20 OP-sensitive and 20 OP-resistant larvaeusing aqueous emulsions similar to those used in Test A. (The resistancerefers to the tolerance towards diazinone). The compounds of Example 1acted in these tests against adults and larvae of Rhipicephalus bursaand OP-sensitive and OP-resistant larvae of Boophilus microplus.

EXAMPLE 7 Action against Erysiphe graminis on Hordeum vulgare

Barley plants about 8 cm in height were sprayed with a spray broth(0.05% of active ingredient) prepared from a wettable powder of theactive compound, 48 hours later, the treated plants were dusted withconidia of the fungus. The infected barley plants were stood in agreenhouse at about 22° C. and the fungus attack was evaluated after 10days. In this test, the compounds of Example 1 acted against Erysiphegraminis.

What is claimed is:
 1. A phenylformamidine of the formula ##STR16##wherein each of R₁, R₂ and R₃ represents hydrogen, C₁ -C₄ alkyl, C₁ -C₄alkoxy, halogen or trifluoromethyl, R₄ represents C₁ -C₄ alkyl and Arepresents --CH₂ --CH₂, --CH₂ --CH₂ --CH₂ --, ##STR17##
 2. Aphenylformamidine according to claim 1 wherein R₁ represents chlorine,bromine, methyl, ethyl, isopropyl or trifluoromethyl, each of R₂ and R₃represents hydrogen, chlorine, bromine, ethyl, isopropyl ortrifluoromethyl and A represents ##STR18##
 3. The phenylformamidineaccording to claim 2 of the formula ##STR19##
 4. The phenylformamidineaccording to claim 2 of the formula ##STR20##
 5. The phenylformamidineaccording to claim 2 of the formula ##STR21##
 6. The phenylformamidineaccording to claim 2 of the formula ##STR22##
 7. The phenylformamidineaccording to claim 2 of the formula ##STR23##
 8. An insecticidal andacaricidal composition comprising an insecticidally or acaricidallyeffective amount of a compound according to claim 1, together with asuitable carrier therefor.
 9. A method for combatting insects andacarids which comprises applying thereto or to the locus thereof, aninsecticidally or acaricidally effective amount of a compound of claim1.